Optimization of biomass production by Chlorella saccharophila UTEX 247 employing response surface methodology

Improved productivities of microalgal biomass tend to play a significant role in biorefineries pertaining to multifaceted applications and the inadequate biomass yield in any particular medium is a bottleneck that must be overcome to achieve such sustainability goals. In our present study, we employed new approach to enhance the cell growth of a potential strain Chlorella saccharophila (UTEX 247), i.e., media engineering perspective. For better biomass yields, the fundamental constituents are the macronutrients within the growth medium consisting of nitrogen (as NaNO3, sodium nitrate), phosphorus (as K2HPO4, dipotassium phosphate) with an additional source of carbon supplementation in the form of NaHCO3, sodium bicarbonate. Our preliminary studies by One Factor at a Time demonstrated no effect on growth with additional carbon supplementation but showed that nitrogen and phosphorus ratios play a significant role in the biomass production. Furthermore, we optimized the biomass yields employing the central composite design associated with the response surface methodology tool to illustrate the combinatorial effects of nitrogen (N) and phosphorous (P). Our results have showed an increase up to 131% dcw in biomass production, i.e., 0.84 g L-1 DCW with 26.4 mM and 0.11 mM of NaNO3 and K-2 HPO4 concentrations, respectively, than the control condition (NaNO3: 17.6 mM; K-2 HPO4: 0.23 mM) yielding a biomass content of 0.64 g L-1 DCW with a coefficient of variance of 5.12%. In conclusion, the new perspective of media engineering predicts and also evaluates the best condition for the specific strain of interest so that the optimized medium essentially produces higher cell biomass along with other biocommodities of industrial significance.